Kevin Crawford

Hello everyone, I am making a thread to ask about the n/a rotary temperatures. I will be purchasing an additional 19 row oil cooler for a dual setup for my car. While cruising my coolant temps run about 185-200. I noticed when I stop at idle my oil temps go up and my coolant temps trail until I start moving again with temps getting up to 220 degrees water and 230-240 oil. This is the main reason why I am running an additional 19 row cooler before I really start driving the car more regularly. I have not driven the car much because of this besides dialing in my ignition issues from previous posts. I live in flordia and mid summer heat can be brutal to make a long story short. This is when I decided to do all my testing to ensure that my car stays reliable year round when I do start driving it more. I have been reading about dual cooler setups or parallel cooler setups mainly in the FD section of the forum because most of the guys have turbos and create alot more heat. Some of the temperatures posted are around 230 water temps and 230-260 oil temps while racing. Am I overreacting with my coolant and oil temps or are the FD owners generally nuts. I am generally curious on how many of the FB/sa owners run a dual cooler setup. Does anyone know the btu ratings needed to properly cool a n/a rotary with the proper ducting?

KansasCityREPU

iTrader: (9)

Couldn't you ran a pusher fan that is triggered when the temp gets to say 220 degrees? Sounds like the issue is lack of air flow. Maybe your clutch fan isn't working? Might check that first.

GSLSEforme

Don't remember if you have a 12A or 13B. If stock 12A,beehive cooler is fine for a street car. 13 B will need an oil cooler,a FMOC is THE way to go. I don't know what you are running now for an oil cooler(s),by the time you cobble together enough cooling to match what you get with a FMOC,WITH a thermostat,you will have spent double the money. You can run a FMOC on a 12A too,most simple,straightforward,cost effective way to go to get a Mazda engineered system,you cannot do better for the money. THEY know what's needed to keep a rotarys oil cool.
Often these aftermarket coolers restrict flow of oil besides not being large enough to cool properly.

Cooling system well designed also. Make sure the radiator is clean,if not sure,have it tested and cleaned. Is the thermostat correct temp for application,have you tested its operation in a pan of boiling water with a thermometer? Can't go wrong with oe Mazda.
Does the cooling fan clutch work properly,been tested? Point is,the factory oil/coolant systems work well-when maintained in good operating condition. So,before you go chasing"problems",looking for fixes,be certain that what your car came with is working as it should.

Kevin Crawford

The motor is a 13b, My fan is a 2500cfm electric puller fan with a shroud. I am running a stock thermostat. I tested it before putting it in the car in boiling water but did not measure what temp it opened at. I was more checking to make sure the thermostat actually opened and wasn't faulty before installing it, It is a stock gsl-se thermostat. I have not tested my radiator, it is a koyo radiator. I have however put my hand on the oil cooler and it is to hot to touch leading me to think it is heat soaking. I have a oil pressure guage and at half throttle I am pushing over 80psi oil pressure so I know I am getting good pressure or flow. The thing that pointed me to the oil cooler was the oil temps. While driving they would stay exactly the same, once I stopped it would increase to say from 170-190 degrees. I would drive again and it would not drop back down only remain constant. However every time I would stop at idle the oil temp would steadily rise and not go back down with me cutting it off around 210-220 oil temps.

KansasCityREPU

iTrader: (9)

Might try going back to a factory fan with fan clutch.

Kevin Crawford

I was afraid you would say that. I probably will go with a fc oil cooler first and see if it makes a difference. If not, I will switch back to a stock shroud/fan and use my electric fan as a pusher.

GSLSEforme

How is your fan configured to run,does it run full time whenever engine is running or is it triggered by some type of thermostat?Is it adjustable,at what temp point do you have it set to turn on? What diameter are fan blades?Is it running at idle when temps are creeping up?
12A or 13B,you didn't answer. If 12A are you running beehive and oil cooler,this is an either one or the other situation. Pressure is not an indication of flow.
What type gauges are you getting readings from,are they accurate,have you ever verified their readings with an infra red thermometer? You should. Check temp at thermostat housing and upper and lower hose. The hose at thermostat housing is most accurate place to check actual operating temp. The readings at radiator hose connections will show temp differential and is an indication how effective radiator is shedding engine heat.
Are you losing coolant,are you running an overflow bottle,do you see a difference in coolant level in bottle between engine cold(overnight) and engine running at 220 degrees on your gauge?

Oil temp can be tested same way,check at engine where oil hose is going to cooler and check at cooler at the line that comes out and returns to engine. Pressure and flow are two different things. Undersized oil cooler will cause oil temps to be higher and will contribute to cooling system temps to be higher,they each need to shed their load of heat.
You can rent an infrared thermometer at a lot of parts stores,or buy one.$30 will get you a decent one.
Post back answers to these questions and temp reading results with infra red thermometer-compared to your gauge readings. Some pics of your radiator/fan/wiring/controller-thermostat and oil cooler(s) will be helpful.
Happy to help you work your way thru your problems,need question answers and test results to direct you in which way to go to determine fixes.Will check your thread for responses.

Kevin Crawford

I have my fan switch set up on a toggle switch for the time being, I always cut the fan on at idle. My motor is a 13b, I do not have a beehive cooler. I will likely be going out tomorrow to take pictures if the weather permits and be purchase a infared thermometer to check over everything. My water temp guage sensor is ran into my water pump housing. My guages are autometer water and oil temp/pressure. The only cooler I have on it right now is a single derale 19 row for the time being because I need more an fittings and line to run another. My oil temp sender guage is ran to a racing beat sandwich/adapter plate under the oil filter. I do not loose any coolant. When the water temp fluctuates the overflow bottle level changes.

mikey D

My track car has a stock radiator, a big setrab mounted directly in front and a cheap summit electronic fan.

water is 180-198 when moving
oil is 180-210

diabolical1

iTrader: (3)

is it this (or something similar? https://derale.com/product-footer/fl...1/51908-detail

my guess is that that's probably the heart of your problem. you mentioned earlier about trying an FC cooler. i think you should probably just go with that and ditch the one you have (and your plans to get a second).

do you still have the shrouding for the undertray?

Kevin Crawford

diabolical1the link you posted of the oil cooler is the exact same one I have. I am unsure of the shrouding you are speaking of? My car doesn't have a undertray either so I am assuming that before I purchased the car it was removed.

GSLSEforme

The bellypan is an integral part of cooling system. It seals against bottom of radiator to insure all air coming in thru front of car goes thru condenser/radiator/oil cooler instead of around it. Try to find a bellypan in a salvage yard,it's worth your time and trouble,not a lot of $$$.

No doubt FB,FC oil cooler will drop that oil temp 40-50 degrees and drop coolant temp some by taking heat load off engine. A proper working clutchfan/radiator would do much better than electric fan you're running and there will be no switch you may forget to turn on with bad consequences for not doing so.

Carl

iTrader: (2)

I came across these the other day if you can't find a belly pan in the junkyard. https://lrbspeed.com/product/safb-undertray/

Carl

Kevin Crawford

I have a wooden splitter that I made for the car. I pulled it off the car to put the new motor in. I guess it is time to put it back on, my theory is that it will do about the same thing a belly pan will if I can seal it correctly. I purchased a fluidyne oil cooler as well that was recommended in a previous thread as an upgrade to the FC cooler. I am overbuilding the cooling because I plan on autocrossing the car and attending track events. I will be changing alot on the car in the next few weeks. Adding ducting from the bumper to the radiator and mounting the new cooler. I had rather take my time and setup everything correctly and have a reliable car to drive. I now have a infrared thermometer to test everything and post results. I just need to get my finals in school out of the way where I can post results. I temporarily did a fan toggle switch because I was unsure of where to add the temperature sensor for the fan relay because my temp guage sensor is mounted in the water pump housing.

GSLSEforme

Find a used bellypan,it's worth the time as it will work better than anything you can cobble up.Look at pic of my car in this thread. The bellypan seals to weatherstrip on bottom of radiator. Weatherstrip available at Home Depot for @ $2.00.It is held to radiator with Red 3M side double sided molding tape. You could delay the ducting to the radiator for oil cooler. All the air comes into front of car into radiator opening,oil cooler mounted there will get 1st shot of that air...as long as you have sealed bellypan in place,that's all that will be needed.
You should have a thermostat inline with the oil cooler,one of the reasons i suggested FB,FC oil cooler,the thermostat is integral to the cooler. This is an added expense for an aftermarket cooler for both the thermostat and the related plumbing that is needed to install it.
KansasCityRepu has posted pictures of a setup he installed on one of his cars,maybe he'll see this thread and post a pic so you can see what it looks like.

Did your radiator fan come with a temp sensor? There are temp sensors that can be slipped into fins in radiator core right below where upper rad hose mounts.

KansasCityREPU

iTrader: (9)

Here is mine.

GSLSEforme

KCR,if you don’t mind,what was cost on the thermostat,looks to be good quality.

KansasCityREPU

iTrader: (9)

It's an Earl's 501ERL. Mine is the older style. They have an update one now. About $125 without the -10AN fittings.

Summitt carries several. https://www.summitracing.com/parts/e...SABEgKqyvD_BwE

chuyler1

iTrader: (1)

I'm running a 12a with the GSLSE front mount, koyorad radiator, a 14" fan with shroud, and the factory belly pan. Even on 95 degree days up here in NH the warmest it gets in traffic is 195 water and maybe 210 oil. Readings are from GM sensors that have been calibrated and verified with a infrared sensor. My fan is set to come on at 60% below 20mph and turn off above 30, but it also has a PWM sensor that will bump it to max speed if the temps rise above 200, I haven't heard it turn on yet.

Nothing about your build leads me to think you should be over working your cooling setup to the point you need multiple oil coolers. Just make sure you have that belly pan for maximum cooling while moving....but it won't make that much difference in traffic when the fan is doing most of the work.

Kevin Crawford

I just took a reading of the temp at idle for about 5 minutes.
Water pump housing after thermostat 176.0
Upper radiator hose 86.4
Lower radiator hose 98.8
Radiator temp 91.0

Oil cooler 193.1
Inlet hose 162.8
Outlet hose 149.9

GSLSEforme

Is this fully warmed up to operating temp as in just measured after driving?

Kevin Crawford

This was not done after driving. This is equivalent to a idle warm up before driving anywhere.

GSLSEforme

Do this after driving at operating temp for several miles. Readings taken at this point are most accurate and will show what to concentrate on to improve #s

Is this as car sits now,with no work done yet? Post your readings after driving. This will become your baseline to compare results to after you do your planned work.

Kevin Crawford

To answer the previously asked question the fan did not come with a temperature switch. I do have a thermostat controller temperature switch that I need to wire in but I am unsure what to do because I am using the temperature port on the water pump housing for my water temp gauge.The #'s I posted are before any work being done. I will be posting results after driving as well.

GSLSEforme

Are you running the fan thru a relay? Post a pic of what you have that you're calling "thermostat controller temperature switch" so recommendation can be made on how to proceed installing.